Background:
The evaluation of somatosensory dysfunction is important for diagnostics and may also have implications for prognosis and management. The current standard to evaluate somatosensory dysfunction is quantitative sensory testing (QST), which is expensive and time consuming. This study describes a low-cost and time-efficient clinical sensory test battery (CST), and evaluates its concurrent validity compared to QST.
Method: Three patient cohorts with carpal tunnel syndrome (CTS, n=86), non-specific neck and arm pain (NSNAP, n=40) and lumbar radicular pain/radiculopathy (LR n=26) were included. The CST consisted of 13 tests, each corresponding to a QST parameter and evaluating a broad spectrum of sensory functions using mechanical and thermal detection and pain thresholds and testing both loss and gain of function. Agreement rate, significance and strength of correlation between CST and QST were calculated.
Results: Several CST parameters (cold and warm detection, cold pain, mechanical detection, mechanical pain for loss of function, pressure pain) were significantly correlated with QST, with a majority demonstrating >60% agreement rates and weak to relatively strong correlations. However, agreement varied among cohorts. Gain of function parameters showed stronger correlation in the CTS and NSNAP cohort, whereas loss of function parameters performed better in the LR cohort. Other CST parameters (vibration detection, heat pain, mechanical pain for gain of function, windup ratio) did not significantly correlate with QST.
Conclusion: Some, but not all tests in the CST battery can detect somatosensory dysfunction as determined with QST. The CST battery may perform better when the somatosensory phenotype is more pronounced.

Background and Aims
Clinicians and researchers often rely on altered neurological integrity tests in the leg to identify radicular pain, however neurological integrity is often not tested in the low back region even in the presence of pain in this region. There have been suggestions that the low back pain itself could be neuropathic in nature in some patients (Baron et al., 2016). This study aims to explore the relationship between quantitative sensory testing (QST) measures in the leg and low back in participants with radicular leg pain to consider if sensory testing should be performed in both areas in clinical practice.
Methods
13 participants (mean age 48.2 SD 13.8, gender (female) 8) with radicular leg pain were recruited from National Health Service spinal clinics in the UK. After assessment with the clinician, a full QST profile was taken from each participant’s affected leg and low back. Z scores were calculated using data from age matched healthy controls. Correlations using Pearson’s if the data was normally distributed or Kendall’s Tau-b if not, were undertaken between QST scores of the low back and leg. Paired t tests or Mann Whitney tests were performed to assess differences in QST scores between the leg and low back regions.
Results
There were no significant correlations (P>0.05) in any of the QST measures between the leg and the low back regions. However, only vibration detection threshold measures showed statistically significant differences between the leg and low back (p<0.001), with the low back region showing greater loss of function (mean -2.84) than the leg (mean -0.61).
Conclusions
Significantly lower vibration thresholds were found in the back compared to the leg. This may suggest some alteration in posterior primary ramus large diameter afferent nerve function, and indicate that the low back pain itself may indeed have a neuropathic component. Our findings suggest that sensory testing of the lumbar spine may be advisable in this group of individuals. The small sample size means that these results must be taken with some caution, however these results warrant further investigation in people with radicular leg pain.

Despite normal neurological bedside and electrodiagnostic, some patients with non-specific neck arm pain (NSNAP) have heightened nerve mechanosensitivity upon neurodynamic testing [1, 2]. It remains however unclear whether this is associated with a minor nerve injury. The aim of this study was to evaluate potential differences in somatosensory function among patients with unilateral NSNAP with and without positive neurodynamic tests and healthy controls.
Quantitative sensory testing was performed in 40 patients with unilateral NSNAP; 23 with positive upper limb neurodynamic tests (ULNTPOS) and 17 with negative neurodynamic tests (ULNTNEG). The protocol comprised thermal and mechanical detection and pain thresholds as well as mechanical pain sensitivity, wind-up ratio and dynamic mechanical allodynia. All parameters were measured in the maximal pain area on the affected side as well as over the corresponding area on the unaffected side. Symptom severity, functional deficits, psychological parameters, quality of life and sleep disturbance were also recorded.
Fifty-seven percent of patients with NSNAP had positive neurodynamic tests despite normal bedside neurological integrity tests and nerve conduction parameters. Clinical profiles did not differ between patient groups. Somatosensory profiling revealed a more pronounced loss of function phenotype in ULNTPOS patients compared to healthy controls. Hyperalgesia (cold, heat and pressure pain) was present bilaterally in both NSNAP group. The ULNTNEG subgroup represented an intermediate phenotype between ULNTPOS patients and healthy controls in both thermal and pressure pain thresholds as well as mechanical detection thresholds.
In conclusion, heightened nerve mechanosensitivity was present in over half of patients with NSNAP. Our data suggest that NSNAP presents as a spectrum with some patients showing signs suggestive of a minor nerve dysfunction.
[1] Elvey RL. Physical evaluation of the peripheral nervous system in disorders of pain and dysfunction. J Hand Ther 1997;10:122-129.
[2] van der Heide B, Bourgoin C, Eils G, Garnevall B, Blackmore M. Test-retest reliability and face validity of a modified neural tissue provocation test in patients with cervicobrachial pain syndrome. J Man Manip Ther 2006;14:30-36.